We all know that particular scent that old people have. It's subtly sweet but also brings to mind decay and mortality. It's complex, like a fine wine. Well, anyway, it turns out that science has spent some valuable time confirming that, in fact, the scent does exist, and it's actually rather pleasing.

The original purpose of this study was to determine if people could figure out another person's age from their smell. They had 41 volunteers sleep in special t-shirts with pads in the armpits for five nights. Then they stuck these body-order-laden pads in jars and grouped the jars by age. It was split into three categories: 20- to 30-year-olds, 45- to 55-year-olds, and 75- to 95-year-olds. They then had 41 new people sniff these jars (which must have been a somewhat unrewarding task) and guess which age group each jar belonged to. They also rated the intensity and pleasantness of each scent.

It turned out they were good at guessing how old people were based on their BO, and they were even better when they were asked to group all the "jars that smelled like old people" together. (Ew, this jar smells like old people!) That means that the old person scent was the most detectable but not because it smelled bad. In fact, the old person scent was rated by the volunteers as the most pleasant and least intense of the different age groups. The reason for this probably has something to do with reproduction, surmises researcher Johan Lundstrom, but what doesn't have to do with reproduction when it comes to the human body? Anyway, Lundstrom says this means that people can't really fake their age: "If you walk around a corner, you don't have to look at someone to know they're older; you can just sniff them out." So, I guess, in this age of plastic surgery, let your nose be your guide.